Strong-current protector.



No. 686,350. Patented Nov. I2, |90I.

A. A. SEELEY & C. SILET.

STRONG CURRENT PROTECTOR.

(Application led Feb. 4, 1901.) (No Model.) 2 Sheets-Sheet I.

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Patented Nov. l2, I90I.

A. A. SEELEY &. C. SILET.

STRUNG CURRENT PROTECTOR.

(Application led Feb. 4, 1901.)

2 Sheets-Sheet 2.

(No Model.)

UNITED STATES PATENT OFFICE.

AARON A. SEELEY AND CHARLES SILET, OF OIIICAGOILLINOIS.

STRONG-CURRENT PROTECTOR.

SPECIFICATION forming part of Letters Patent No. 686,350, dated November12, 1901.

Application led February 4,1901. Serial No. 45,961. (No model.)

To all whom t may concern:

Be it known that we, AARON A. SEELEY and CHARLES SILET, citizens of theUnited States, residing at Chicago, in the county of Cook and State ofIllinois, haveinvented certain new and useful Improvements in Strong-Onrrent Protectors, of which the following is a specification.

Our invention relates to improvements in that class of devices Jforprotecting electrical instruments against the action of electriccurrents of excessively high electromotive force which operate byautomatically breaking the circuit in which such instruments areinterposed whenever the strength of the electric current exceeds apredetermined limit.

The object of our invention is to provide a compact self-containeddevice for automatically throwing open an electric circuit whenever thestrength of the current passing over such circuit shall exceed apredetermined limit.

Another object of our invention is to provide such a device which, whileit will automatically protect instruments in the circuit from currentsof excessively strong electromotive force, will do so in such a way thatthe circuit may be again closed immediately thereafter and theinstrument simultaneously reset without delay, without the requirementof skill, and without renewing any parts.

Another object of our-invention is to provide such a device which shallsimultaneously throw open the circuit in which itis interposed and closea local circuit, whereby an alarm or signal may be given indicating thatthe main circuit has been broken and at what point, thus enabling anoperator to immediately proceed to the requisite point and reestablishthe circuit.

A further object of our invention is to provide such a device whichshall be so adjustable that the same instrument may be set so as toautomatically operate to break the circuit when the strength of thecurrent passing therethrough shall exceed varying predetermined limits,as may be deemed desirable from time to time.

These and such other objects as may hereinafter appear are attained bythe devices illustrated in 'the accompanying drawings, in which- Figurel is a side elevation of our device. Fig. 2 is a plan view of our deviceseen from above. Fig. 3 is aplan viewseen from below. Fig. 4 is a detailillustrating more clearly the operation of ourautomatic cnt-out. Fig. 5shows a modiiied form of our device; and Fig. 6 is a sectional detailthrough a portion of our device, showing how a lightning-arrester may beinterposed therein.

Similailetters of reference indicate the same parts in the severalfigures of the drawings.

Referring by letter to the accompanying.

drawings, A is abase, of any suitable insulating material-such, forinstance, as slateupon which are mounted binding-posts B, to which theline-wires of an electric circuit are connected. These binding -postsare electrically connected-as, for instance, by the metallic strip b,Fig. S-With the spring terminals or electrodes C, which in turn areelectrically connected,by means ofthe bridges D, with the springterminals or electrodes E, which are again connected by any suitableelectrical conductor, as e, Fig. 3, with one end of the coils with whichthe electromagnets F are wound, the other ends of these coils beingelectrically connected with the bindingposts G, to which are attachedthe circuitwires leading to the instrument or instruments interposed insuch circuit. Also mounted upon the base A are the posts H, to which arepivotally attached the retaining-arms I, upon which are mounted theinsulating-buttons J. Each retaining-arm I is also preferably providedwith the adjustable tongue t, which is adapted to engage a slot 7c inthe armatures K. Said armatures are pivotally mounted between the lugsZof the plate L.

M is an armature-spring adapted to hold the armature in opposition tothe attraction of the electromagnets F.

N is an armature-adjustment screw mounted upon the stem a of the plateL.

CZ represents springs adapted to throw their respective bridges D out ofcontact with the electrodes C E.

In the preferred form of our device is a coiled spring mounted upon thestem d ot IOO the bridge D and having its upper end secured to thebridge D, as at 0, Fig. 4t, and having its lower end attached tothebindingscrcw O, said binding-screw connecting with the line-wires of alocal alarm-circuit, and in our preferred construction an electrode P isalso mounted upon the base A and at one side of one of the bridges D,said electrode constituting the other terminal of said localalarm-circuit.

It is well understood that if electrical instruments-such astelephones,electrielights, and other electrically-operated devices aresubjected tothe action of a current of greater strength or higherelectromotive force than the electrical capacity of such instruments theaction of such excessive current will result in seriously damaging oreven destroying such instruments or parts thereof, with consequent delayuntil the instruments can be repaired or replaced. The desirability of adevice which shall automatically and instantaneously break the circuitat a suitable point, so as to protect such instrument whenever from anycause an excessively strong current shall be thrown into the circuit, isquite apparent, and various means have been devised to accomplish thispurpose, one of the commonest being fusible plugs, which 'are interposedin the circuit and which are melted, so as to break the circuit,whenever subjected to an excessively strong current. Vhen thishappens,the plugs so fused must be located and replaced, a proceedingrequiring some skill and often causing a considerable delay until thefused plugs are found and a skilled electrician can be procured toreplace them, theinstruments, lights, zc., dependent on such electricalcircuit being meanwhile out of service. There are also disadvantagesattending the use of fusible plugs in attempting to gage or adjust thepoint at which they will promptly fuse.

Our improved device may be readily set so as to be operated by a currentof practically any strength which may be decided upon, and when thecurrent reaches that point our device operates instantaneously andpositively, but without the destruction of any of the parts, and isready to be instantly reset, so as to effectively reestablish thecircuit and so as to be ready to immediately again break the currentwhenever the strength of the cu rrent shall reach the same predeterminedpoint.

The operation of our device is as follows: The device being set as shownin Fig. l and attached to the line-wires of an electric circuit at thebinding-posts B B G G, the current will come in through one binding-postB and will thence pass along the metallic strip b to the electrode C,across the bridge D to the electrode E, through the conductor e, throughthe coils 0f the electromagnets F, the respective coils of each pair ofmagnets being oppositely wound, thence to one binding-post G, and out onthe line and through any instrument or instruments interposed on theline. The current then comes back to the other binding-post G and thencecontinues back through the other pair of electromagnets and the otherelectrodes, bridge, die., to the other binding-post B and thence out tothe line and back to the dynamo. XVith the current turned on, asdescribed, the electromagnets exert a continuous attractive force uponthe armatures K, the force of which is eounteracted by three opposingelements: first, the distance between the elecl[romagnets and theopposing faces of the armatures; second, the opposing force cf thearmature-springs M, and, third, the friction between the opposingsurfaces of the slots 7u on the armatures and the terminal tongues tupon the controlling-arms l, said opposing surfaces being held inforcible contact by the pressure of the springs CZ exerted upwardlyagainst the bridges D and through them against the insulating-buttonsy', attached tothe arms I.

vVhenever the strength of the current passing through our instrument issufficient to so strongly magnetize the magnets F that the magneticattraction exerted by them is sul'icient to overcome these opposingforces, then armatures K are drawn to the magnets, thereby releasing ortripping the arms I, which, together with thebridges D, are immediatelythrown upwardly or outwardly from the baseplate A, and in our preferredconstruction as soon as the faces of the angular arms of the bridgesDare carried out of contact with the electrodes C E the spring (Z throwsthe bridges D to a position at right angles tothe position occupied bythem when the instrument was set. Vhen this happens, the terminal P,which acts as a stop to the rotation of the bridge D, makes electricalcontact with the bridge D, and thereby a local circuit passing throughthe binding-screw O, the spring d, the bridge D, and the terminal Pisclosed and an alarm or signal of any suitable character is given,indicating that the circuit has been broken. rlhis alarm can, ifdesired, be made to indicate the exact point at which the break in thecircuit has occurred. In the simpler form of our device (shown in Fig.5) no such local circuit is provided, and the action of the coil-spring(l simply results in throwing the bridge D upwardly or outwardly out ofcontact with the electrodes C E.

lf our device is used on a grounded circuit, then it may be constructedin its simplest form,comprisingonlyone set of binding-posts, electrodes,and eleetromagnets and only one arm, bridge, and armature; but where itis used in a metallic circuit it is necessary in order to prevent anypossibility of the circuit being carried through the ground to theinstru nient, as may very readily happen if such a lightning-arrester asis shown in Fig. b' is IOO IOS

IIO

used with our device, that our device should be constructed in pairs, asshown in Figs. 2 and 3.

By controlling the three iniiuences or forces which oppose the magneticaction of the electromagnets upon the armatures we obtain any desiredadjustment in setting our apparatus. The armaturespring, which may beany suitable form of spring, as well as that shown in the drawings, maybe put under greater or less tension, as may be desired. By means of theadjustment-screw N and the adjustable tongue c' the space between theopposing faces of the armature and electromagnets may be lessened orincreased at will, and by means of the adjustable tongue@l the trip maybe adjusted as delicately as occasion may require.

We iind that by making one of the electrodes, as E, in such form thatthe bridge D will not be brought in contact therewith until the tongueor plate t' is about to engage the slot lo the annoyance of having thearmature drawn to the electromagnets just before the trip is set may beavoided.

In Fig. 6 we have shown in vertical section a lightning-arrester whichmay be conveniently interposed in our device, as shown in Fig. 5. Thisarrester consists of a pair of terminals or electrodes Q R, to theopposing faces of which are secured sections of carbon S, which areseparated by small strips of rubber or other insulating material s. Theterminal Q is electrically connected with the terminal C and with thebase A by the screw c, which passes through the base A. The terminal Rmay be conveniently secured to the base A by means of the screw h, whichpasses through the base A and into the standard H, between which and theupper surface of the plate the horizontal portion of the terminal R maybe firmly secured, and by means of the screw h the terminal R may beelectrically connected in any convenient manner with a binding-post, towhich is attached a groundwire.

When our device is used inthe form shown in Fig. 2 for a metalliccircuit,we prefer to use two of these lightning-arresters,the electrodesQ being respectively connected with the electrodes C and the electrodesR being respec tively connected with the standards or posts II. Whenthis is done, we find a convenient way of connecting the twolightningarrest ers with the ground consists in securing to the bottomof the base A a metallic strip T by means ot` the screws h and the screwu, which latter screw passes through the base and secures thebinding-post U to the upper surface of the base. This binding-post is intended for connection with a ground-wire.

Having thus described our invention, what we claim, and desire to secureby Letters Patent, is-

1. In an automatic cutaont device, the eombination of a pair of terminalelectrodes, a spring-actuated bridge normally out of contact with saidelectrodes, an arm detached "D CU) from said bridge adapted to hold saidbridge against spring-pressure so as to electrically connect saidelectrodes, said arm being held in closed position by engaging a catchupon an armature, and an electromagnet adapted to release said catch,substantially as described.

2. In an automatic cutout device, the combination of a pair ot terminalelectrodes, a bridge located therebetween but normally out of contacttherewith, an arm detached from said bridge adapted to hold said bridgeagainst spring-pressure between said electrodes so as to electricallyconnect the same, a pivoted armature, a catch thereon adapted to engageand hold said arm in closed position, and an electromagnet adapted torelease said catch, substantially as described.

3. In an automatic cut-out device, the combination oi a pair of terminalspring-electrodes, a bridge norm ally out of contact therewith, meansdetached from said bridge for holding said bridge wedged between saidelectrodes and against spring-pressure, an armature, a catch thereonadapted to hold said bridge-confining means in closed position, and anelectromagnet adapted to release said catch, substantially as described.

4i. In an automatic cut-out device, the combination of a pair ofterminal electrodes, a spring-actuated bridge adapted to electricallyconnect the same but normally out of contact therewith, a pivoted armdetached from said bridge and adapted to hold said bridge againstspring-pressure and in contact with said terminal electrodes so as toelectrically connect the same, an armature, a catch upon said armatureadapted to engage and hold said arm in closed position, an electromagnetadapted to actuate said armature so as to release said catch, andadjustable means for holding said armature in opposition to theelectromagnetic force of said magnet, substantially as described.

5. In an automatic cut-out device, the com=l bination of a pair ofterminal electrodes, a bridge adapted to connect said electrodes butnormally out of contact therewith, means for normally holding saidbridge out of contact with said electrodes, a pivoted arm detached fromsaid bridge adapted to hold said bridge in contact with said electrodes,an electromagnet, an armature actuated thereby, and a catch upon saidarmature adapted to engage and hold said arm in closed position,substantially as described.

6. In an automatic cnt-out device, the combination of a pair of terminalelectrodes, a bridge adapted to electrically connect the same butnormally out of contact therewith, means detached from said bridge fornormally holding said bridge at an angle to the posim tion occupied byit when in contact with said electrodes, means detached from said bridgefor holding said bridge in contact with said electrodes, an armature, acatch upon said armature adapted to hold said arm in position IIO forkeeping said bridge in contact with said electrodes, and anelectromagnet adapted to actuate said armature so as to release saidarm, substantially as described.

7. In an automatic cut-out device, the combination of a pair of terminalelectrodes, a bridge adapted to electrically vconnect the same butnormally out of contact therewith, means for normally holding saidbridge at an angle to the position occupied by it when in contact withsaid electrodes, an arm adapted to hold said bridge in contact with saidelectrodes, an armature, a catch upon said armature adapted to hold saidarm in position for keeping said bridge in contact with said electrodes,an electromagnet adapted to actuate said armature so as to release saidarm, and a local circuit which is closed by said bridge when in itsnormal or released position and which is broken' when said bridge is incontact with said electrodes, substantially as described.

8. In an automatic cut-out device, the combination with a base, of apair of terminal electrodes, a bridge adapted to electrically connectsaid electrodes but normally out of contact therewith, means fornormally throwing said bridge out of contact with said electrodes,anelectric circuit closed by said bridge when in its normal position andbroken when said bridge is in its set position, an arm detached fromsaid bridge for holdingsaid bridge in its set position in contact withsaid electrodes, an armature, a catch adapted to hold said arm in itsclosed position and actuated by the movement of said armature, and auelectromagnet adapted to actuate said armature so as to release saidcatch, all of said parts being mounted upon said base, substantially asdescribed.

9. In an automatic cut-out device, the combination of abase, a pair ofspring-electrodes, a T-shaped bridge mounted therebetween and adapted toconnect said electrodes but normally held out of contact therewith, aspring mounted upon the stem of said bridge and adapted to throw saidbridge when released out of contact with said electrodes, a pivoted armadapted to hold said bridge in contact with said electrodes, a pivotedarmature, a catch upon said armature, adjustable means upon said arm forengaging said armature, an electromagnet adapted to actuate saidarmature so as to release said catch, and adjustu able means for holdingsaid armature away from said electromagnet, substantially as dcscribed.

AARON A. SEELEY. CHARLES SILET. Witnesses:

F. H. DRURY, O. R. BARNETT.

